With the development and popularization of mobile communication technologies, the mobile communication terminals are applied more and more, and any mobile communication terminal cannot leave without antennae, so antennae play a very important role in mobile communications.
Since the printed antenna that can be printed on a printed circuit board (PCB) has the following features: the structure is simple, the performance is good, the profile is low, and it can be integrated on the PCB easily, it is widely applied in terminal antennae.
In the existing printed antennae, antennae that can radiate dual-frequency, tri-frequency and multi-frequency have been used widely; however, in the relevant art, tri-frequency and even higher-frequency antennae require two or more feed points and also require additional switch circuits to control the two or more feed points; in other related arts, there is also the case where several single-frequency antennae are used to realize multi-band antennae, and in such arts, switch control circuits are used to control different single-frequency antennae to operate in different bands to obtain the effect of multi-frequency radiation.
In the above-mentioned related art, there are at least the following technical problems:
for a multi-band antenna with multiple feed points, since it is required to design a plurality of feed points, there is the technical problem whereby the structure is complicated and there are many feed points;
for the case where several single-frequency antennae are controlled with the switch control circuits, since it is required to add switch control circuits additionally and there are also a plurality of feed points, there is also the technical problem whereby the design is complicated, the structure is complicated and there are many feed points.